This invention relates to a coated article including a metal or metal nitride layer provided between an IR reflecting layer (e.g., Ag layer) and an oxide barrier layer (e.g,. NiCrOx), and a method of making the same.
Coated articles provided for solar control purposes are known in the art. For example, see U.S. Pat. No. 5,344,718, which discloses a layer stack of: glass/Si3N4/NiCr/Ag/NiCr/Si3N4. In coatings such as this, NiCr barrier layers are commonly used to protect the Ag (silver) in low-E type coatings.
Unfortunately, metallic NiCr is characterized by high absorption which reduces transmittance of the final coated article. Due to this high absorption problem, those in the art desiring products with high visible transmission have been forced to use very thin NiCr barrier layers. For example, the NiCr layers in the aforesaid ""718 patent are xe2x80x9cless than about 7 xc3x85xe2x80x9d thick, in order to obtain the desired visible transmission. The thinner such layers are, the less barrier functionality and protection they provide. Consequently, those skilled in the art have been seeking to increase barrier layer transmission by introducing oxygen and/or nitrogen to NiCr barrier layers (e.g., see U.S. Pat. No. 6,014,872 at col. 4, lines 40-50).
Consider a layer stack of glass/Si3N4/NiCrOx/Ag/NiCrOx/Si3N4. While the NiCrOx protective barrier layers are more transparent than NiCr protective barrier layers, they have their problems. For instance, the use of NiCrOx protective barrier layers contacting the Ag layer on respective sides thereof can sometimes lead to problems with respect to durability and/or heat treatability. It is believed that during deposition (e.g., via sputtering) of a coating including NiCrOx protective barrier layers, the Ag layer is exposed to the oxygen plasma (and thus chemically active atomic oxygen in that plasma) used in depositing the NiCrOx; this is especially true with respect to the top surface of the Ag layer when an upper NiCrOx protective barrier is applied directly thereto. The exposure of the Ag to this oxygen inclusive plasma is believed to sometimes lead to Ag adhesion problems.
In view of the above, it will be apparent to those skilled in the art that there exists a need for an improved barrier layer(s) structure for protecting an IR reflecting layer (e.g., Ag).
An object of this invention is to provide an improved barrier layer(s) structure for protecting an IR reflecting layer such as Ag in a coated article, and a corresponding method of making the same.
Another object of this invention is to provide a barrier layer(s) structure which is capable of protecting an IR reflecting layer, and which is both fairly transmissive to visible light and enables a durable final coated article.
Another object of this invention is to fulfill one or more of the above listed objects and/or needs.
In certain example embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a coated article comprising: a glass substrate; a coating supported by the glass substrate, wherein the coating comprises a first dielectric layer, a first NiCrOx inclusive layer, an Ag inclusive layer, a second NiCrOx inclusive layer, and a second dielectric layer, wherein the Ag inclusive layer is located between the first and second NiCrOx inclusive layers; and wherein the coating further includes a metal or metal nitride protective contact layer located between and contacting the Ag layer and one of the NiCrOx inclusive layers.
In other example embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a coated article including a coating supported by a substrate, the coating comprising: a NiCrOx inclusive layer; an Ag inclusive layer; and a metal or metal nitride layer located between and contacting each of the NiCrOx inclusive layer and the Ag inclusive layer.
In other example embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a coated article including a coating supported by a substrate, the coating comprising: an oxide layer including an oxide of a metal or metal alloy; a metallic infrared (IR) reflecting layer; a metal or metal nitride protective contact layer located between and contacting each of the metallic IR reflecting layer and the oxide layer; and wherein the metal or metal nitride contact layer comprises the same metal or metal alloy as is in the oxide layer.
In still further embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a method of making a coated article, the method comprising: providing a glass substrate; depositing a first dielectric layer so as to be supported by the substrate; depositing an Ag layer on the substrate over the first dielectric layer; depositing a metal or metal nitride contact layer on the substrate directly over and in contact with the Ag layer; depositing a layer comprising NiCrOx on the substrate directly over and in contact with the metal or metal nitride contact layer; and
depositing another dielectric layer on the substrate over the layer comprising NiCrOx.